Lost all pressure while pressure fermenting Caribou Slobber

[iandanielursino]

I just did my first brewday on Saturday. I made a partial extract caribou slobber kit because someone gave me an old one, the yeast was new though I got a new pack of Windsor at the LHBS.

I brewed in my mash and boil 2, mixed all the crap in, boiled for 60 minutes adding hops and all that, then pumped through a convoluted counterflow chiller into my conical's top port (spike CF10), its just under 5 gallons that was transferred (a little spilled when my hose blew off). One alteration I made to the recipe was to add water until it was 5.5 gallons and then boil down to 5 gallons instead of adding water at the end to make sure everything was sterile.

Another change which was probably a mistake since I should go simple at first was I set up the PRV and figured I'd see how high the pressure would get out of curiosity and because I was worried the room might get too hot during the day.

We pitched in the evening at around 70 degrees and the next morning it was at 6 PSI but I had a slow leak because I installed the gasket upside down, so I dropped pressure, reinstalled the gasket, and buttoned everything back up. Within a couple hours it was up to 10 PSI, and while the top was off I observed an impressive 4 inch or so krausen. The second morning it was at 5 PSI, and by the end of that day it was 0 PSI where it has remained. It is now the third morning.

Temp has been kind of erratic, should be 60-70 though, usually its around 66, targeting 68.

I'm guessing I should take a gravity reading to see how far it got before it stalled, but my question to you guys is, is it possible that all my pressure went away just because of suckback when the fermentation stalled or is this an equipment failure? That seems like a LOT of pressure to get rid of in that way. After I flipped the lid gasket there were no sounds to indicate that there was a leak so I'm not sure how it could be equipment failure. Since I started losing pressure I tightened the 15 PSI PRV all the way down so it shouldn't be letting out any gas. I don't have a CO2 cannister to test the system with, any ideas about how to test?

It seems like a paradox, if the pressure has gone down without venting it must have dissolved more CO2 but if it sits at 0 PSI won't the CO2 eventually come out of the solution?

 

[T Murph]

It may be the gasket itself. I have a CF5 that has given me the exact same problem. Spike sent a replacement gasket that is beveled on top and bottom. Use a very small amount of beer lube or petroleum jelly on both sides of the gasket and tighten the clamp down very tight. I just experienced this a few weeks ago. I received the replacement gasket and installed it after I transferred my beer and got it cleaned up. I pressurized it to 15 psi and left it to see if it holds pressure. I work out of state so I won't know until I return next week if it is still holding. But it was holding 15 psi when I left so we'll see. You may want to contact Spike, their customer service is great.

 

[iandanielursino]

So just cuz' I don't' hear a hiss doesn't mean it isn't leaking?

Without fully removing the lid I just reinstalled the band and tightened it more and tightened all the clamps in the headspace. It wasn't quite 1/4 inch like the manual says because I thought it was 1/2 inch, but it was almost 1/4 inch, now hand tight and somewhere like 1/8th to 3/16th. I've hit the pressure drop plunger a couple times in the last day and each time plus when I was messing with the lid I got smells and sounds indicating that there is in fact trace pressure and thus I suppose fermentation in there.

It could be that the gasket isn't perfectly installed, I did do it quickly because I had done it upside down at first and was in a hurry trying to avoid oxidation.

If it was just because I didn't have the lid on tight enough or something I wonder if it's too late to get a positive number to show up on my gauge to let me know.

 

[sibelman]

You may find additional Spike pressure/leak wisdom among these HBT postings.

 

[iandanielursino]

similar to what is mentioned in this thread I heard a slight hissing/bubbling from the ball lock post so I tightened it carefully until it went away, hopefully it'll pressurize now Spike Conical- observations and best practices

 

[Chorgey]

I don’t have a Spike conical but I do have the All In One PRV. Mine leaked at the gauge. I had to tighten it with a wrench to correct the leak

 

[iandanielursino]

This is making me freaked out about how the spike manual says to remove the gauge for cleaning.

I wonder if any alternative cleaning method is possible such as blocking off the bottom TC fitting and then filling the cup with PBW while pumping the plunger.

I only got the spike PRV because I thought it was effectively thread free, if I knew I was going to unscrew something for cleaning I would have got Ss brewtech's and just added a ball lock and a gauge to the setup.

 

[doug293cz]

I'm guessing I should take a gravity reading to see how far it got before it stalled, but my question to you guys is, is it possible that all my pressure went away just because of suckback when the fermentation stalled or is this an equipment failure? That seems like a LOT of pressure to get rid of in that way. After I flipped the lid gasket there were no sounds to indicate that there was a leak so I'm not sure how it could be equipment failure. Since I started losing pressure I tightened the 15 PSI PRV all the way down so it shouldn't be letting out any gas. I don't have a CO2 cannister to test the system with, any ideas about how to test?

It seems like a paradox, if the pressure has gone down without venting it must have dissolved more CO2 but if it sits at 0 PSI won't the CO2 eventually come out of the solution?

Suck-back does not occur just because fermentation stops. CO2 is in solution in the beer when it is formed. It comes out of solution (and gets vented or pressurizes the headspace) because there is more CO2 in solution than would be in equilibrium with the CO2 in the headspace (determined by CO2 partial pressure in the headspace and beer temperature.)

If you drop the temperature of the fermenter, the CO2 partial pressure in the headspace will decrease because of the cooler temperature. Also, when you cool the beer, the equilibrium concentration of CO2 in the beer (at a given headspace partial pressure) increases, so the headspace pressure will slowly decrease even more due to CO2 being reabsorbed into the beer. But, you didn't cool the fermenter, so this whole paragraph doesn't apply to your situation.

Bottom line: you lost CO2 pressure in your fermenter due to a leak, not CO2 being reabsorbed into the beer.

Brew on

 

[sibelman]

tightened it carefully

Yes. In my experience, the ball lock post must be just tight enough, but not too tight. I wish it were more like the ball lock posts on my kegs. But once I got it dialed in, it seems okay.

 

[iandanielursino]

Suck-back does not occur just because fermentation stops. CO2 is in solution in the beer when it is formed. It comes out of solution (and gets vented or pressurizes the headspace) because there is more CO2 in solution than would be in equilibrium with the CO2 in the headspace (determined by CO2 partial pressure in the headspace and beer temperature.)

If you drop the temperature of the fermenter, the CO2 partial pressure in the headspace will decrease because of the cooler temperature. Also, when you cool the beer, the equilibrium concentration of CO2 in the beer (at a given headspace partial pressure) increases, so the headspace pressure will slowly decrease even more due to CO2 being reabsorbed into the beer. But, you didn't cool the fermenter, so this whole paragraph doesn't apply to your situation.

Bottom line: you lost CO2 pressure in your fermenter due to a leak, not CO2 being reabsorbed into the beer.

Brew on

Right makes sense, the pressure drop from the system finally reaching equilibrium couldn't ever bring it lower than atmospheric pressure without the temperature changing because that would mean CO2 had left the system.

I'll just continue fermenting this batch like normal, the sunny weather ended up going away so I'm not worried about esters anymore I've started instead closely monitoring the space heater that's keeping that area warm to make sure it doesn't get too cold, and it obviously still has a tiny amount of positive pressure. I guess since I don't have a CO2 tank yet my next batch (after cleaning and inspecting everything and making sure the NPT parts are at a good torque with intact teflon tape) is going to be a "quick lager" at high temp so I can spray it with soapy water and check for leaks. I was hoping to do something simple like a SMaSH golden for my first all grain brew but oh well.

 

[T Murph]

To identify the last leak with my CF5 I filled it about half way with PWD and water, pumped in 15 psi Co2, placed it on its side on the bar then slightly rolled it until I found PBW coming out. Mine had many things contributing to my leaks. 1 the gasket was the original that failed to seal, you could see bubbles around the wetted lid. 2 a TC on the lid wasn't sealed properly. 3 and finally a replacement adjustable PRV was leaking from inside the prv. I'm hoping when I get home this weekend that it is still holding pressure.